As the noose tightens on ISIS controlled Mosul, the Iraqi Kurdish armed forces, otherwise known as the peshmerga, are at the forefront of the US-led coalition’s efforts against the ‘Islamic State’ in Iraq. Within a couple days of the Iraqi government’s announcement of the beginning of the battle for Mosul on October 17, the peshmerga had quickly retaken dozens of villages and hundreds of square miles from ISIS control north and east of the city.

While the media trumpets the Iraqi Kurdish armed forces as unified, dependable, and nonsectarian compared to their Iraqi Arab counterparts, they simultaneously obscure the peshmerga’s true identity, capabilities, and goals. A more informed understanding of the peshmerga reveals key limitations that will complicate the Mosul offensive going forward.

Peshmerga Disunity

First, the Iraqi Kurdish armed forces are deeply divided. The peshmerga brigades are split between those that are affiliated with the two dominant political parties in Kurdistan, the Kurdistan Democratic Party (KDP) and the Patriotic Union of Kurdistan (PUK). This rift is a legacy of a bitter civil war between the KDP and PUK from 1994 to 1998 when their peshmerga units fought each other for power within Kurdistan. As a result of the power sharing agreement that ended the conflict, two rump governments emerged within the reunified Kurdistan Regional Government (KRG): the KDP’s based in Erbil, and the PUK’s based in Sulaymaniyah. The PUK and KDP forces have traditionally respected each other’s spheres of influence and authority in the PUK’s ‘green zone’ of Sulaymaniyah and the KDP’s ‘yellow zone,’ of Erbil and Dohuk. The Kurdistan regional government’s subsequent efforts to unite the two party’s respected armed forces have proved ineffective.

As a result, both groups have their own operational procedures and rules of engagement that could fray the offensive’s cohesion in the battle for Mosul. For instance, the KDP’s peshmerga have previously incorporated Iranian Kurdish fighters within their ranks and they have a history of cooperating with Turkish forces, troops that Baghdad has threatened to combat if they participate in the recapture of Mosul. The PUK, on the other hand, have often enlisted the aid of fighters from the Kurdistan Worker’s Party (PKK), which the US, Turkey, and much of the international community has labeled a terrorist organization. The coalition’s offensive could quickly unravel if Turkish soldiers or PKK militants become involved in the campaign. The KDP and PUK’s likely future jockeying for conquered territory and further leverage over the other in the post operation phase may exacerbate discord within the peshmerga and hamper the coalition’s efforts.

Unwelcome Liberators

One might expect that the Arabs living under ISIS control in Mosul would welcome liberation at the hands of Kurdish armed forces. Nevertheless the Sunni population would likely consider the Iraqi Kurds unwelcome liberators. A parallel can be drawn with the longstanding distrust between the Arabs and Kurds in Syria. An activist group in Raqqa named Raqqa is Being Slaughtered Silently reported that the Sunni Arab population in ISIS-ruled Raqqa would reportedly resist a Kurdish liberation force rather than welcome it. They fear that if a well equipped, US supported, and predominately Kurdish force retakes Raqqa, that the Kurds will subjugate the population and take away Arab land.

Similarly the Iraqi Arab and Kurdish populations have a long history of animosity and confrontation. Saddam Hussein’s chemical weapons attacks against the Kurds, as well as his ‘Arabization polices’, which drove many Kurds from their homes, are bitterly remembered. On the other hand, the marginalized Sunni Arabs are trying to preserve as many of their former prerogatives as they can while they view the Kurds as US collaborators or worse. The Iraqi Kurds have been accused of exploiting the war against ISIS to incorporate liberated Arab land into the Kurdistan region. For instance, the peshmerga have been blamed for displacing Sunni Arabs from recaptured Arab towns, destroying their homes, and preventing their return to Sinjar province in Iraq. The KRG categorically denies the allegations. They blame the destruction of homes on US-led coalition airstrikes and ISIS fighters while pointing to the large number of Sunni refugees they are hosting in Iraqi Kurdistan as proof of their good intentions. Ultimately, the closer the peshmerga approach the Sunni dominated city of Mosul, the more Sunni resistance they will likely encounter.

The mutual animosity between the Kurds and the Sunni Arabs explains why the head of the KRG government, Massoud Barzani, has stated that the peshmerga will not enter the predominately Sunni city of Mosul while Iraqi Prime Minister Haider al-Abadi simultaneously reassured the coalition that only Sunni Arab Iraqi security forces will enter the city. Nevertheless if the fighting in the city goes poorly, the peshmerga may be asked to intervene thus risking sectarian violence.

Fighting for a Stronger Kurdistan

The failure of the Iraqi government to protect and provide for the Kurds against ISIS has further driven the PUK and the KDP to focus on bolstering their own security rather than that of the feeble Iraqi state. For instance once the Iraqi Security Forces (ISF) fled in the wake of ISIS’s capture of Mosul in June of 2014, the Kurds saw an opportunity to fill the void. The peshmerga swiftly occupied ninety percent of the ‘disputed territories’ between Erbil and Baghdad (Kirkuk, Diyala, and Nineveh), whose status decades of countless diplomatic efforts had failed to resolve. The KRG’s acting President Massoud Barzani and Prime Minister Nechirvan Barzani calls for an independence referendum for Iraqi Kurdistan has only made the vision of maintaining a unitary Iraqi state after the recapture of Mosul look dimmer.

Another source of tension is the uncertainty over whether the Iraqi government or the KRG will retain control over the recaptured territory surrounding Mosul. The Kurdish regional government for its part has repeatedly claimed that all territory retaken by the peshmerga will eventually be incorporated within the largely autonomous Kurdish region. In addition, Prime Minister Barzani appeared to issue a veiled warning to the Iraqi government that the KRG might want to take over the administration of Mosul after it was liberated. How this will conflict with the agenda of the governments in Baghdad, Ankara, Tehran, and Washington in the future remains to be seen.

In closing, the coalition’s offensive against Mosul is an unprecedented and vulnerable one. With the myriad of competing actors including Turkey, Iran, the Iraqi military, the Shi’ite Popular Mobilization Forces, the United States, Russia, and the peshmerga trying to shape the campaign, the coalition rests on unsteady foundations. Keeping the peshmerga’s divisions, goals, and limited capabilities in mind will help coalition forces better navigate the pivotal months ahead.